Air conditioning systems



AIR CONDITIONING SYSTEMS Original Filed Aug. 17, 1959 JNVEN TOR. mmm 1W. 'wmy ATTQQNEY.

United States Patent 3,318,371 AIR CONDITIONING SYSTEMS Charles W. Egbert, Ridgewood, N.J., assignor to Borg- Warner Corporation, Chicago, Ill., a corporation of Illinois Continuation of application Ser. No. 834,069, Aug. 17, 1959. This application July 1, 1963, Ser. No. 292,801 5 Claims. (Cl. 1652) This application is a continuation of application Serial No. 834,069, filed August 17, 1959, and now abandoned.

This invention relates to zoning the returned heatexchange fluid of air conditioning systems. The invention more particularly relates to zoning the returned heat-exchange fluid in the type of air conditioning system as set out in the application of Robert D. Blum, Serial No. 710,751, filed January 23, 1958, and now Patent No.'3,024,008 granted March 6, 1962, assigned to the assignee of this invention.

In a system as set out in the Blum application, various rooms within a building to be conditioned are provided with room conditioning units. These units are supplied with both heated and chilled water (heat-exchange fluid) for flow through the unit, depending on whether it is desired to heat or cool the particular room. The Water returning from the room units all mix in a common return line, part of it going to a water cooler and part to a water heater. This invention specifically relates to a method of zoning this returned water, whereby, water returning at a temperature above a desired temperature will be routed to the heater, with water at a lower temperature routed to the cooler.

In order to accomplish this, the building to be conditioned is divided into zones for the returned water only. Generally, there are but four zones, these being North, South, East and West. It will be apparent, however, that the building may be zoned in any manner, the criterion being that the rooms in any particular zone be either heating or cooling so that the returned water from the various units of a particular zone be generally at about the same temperature. When the building is zoned according to the exposure, it will be apparent that most of the rooms in any one exposure will be either heating or cooling, dependent on the sun load. It will be rare that, in one exposure, some rooms will require heating and some require cooling.

In carrying out the invention, the various zone return lines each lead into a three-way valve, which will divert the returned water to a hot water header or a chilled water header, depending on its temperature.

A principal object of the invention, therefore, is to provide a method of zoning the returned water in an air conditioning system of the type wherein a supply of heated and chilled water is available for flow through a room conditioner.

A further object is to provide an air conditioning system of the type wherein a supply of chilled and heated water is available for flow through an air conditioning unit, and wherein means are provided for collecting returned water of like temperature and routing that water to a chilled water header or a heated water header, depending on its temperature.

The invention consists of the novel constructions, arrangements and devices to be hereinafter described and claimed for carrying out the above-stated objects and such other objects as will appear from the following description of a preferred embodiment of the invention described with reference to the accompanying drawings, in which:

The single figure is a schematic representation of the hereinabove disclosed air conditioning system.

3,318,371 Patented May 9, 1967 Turning now to the figure, -a building to be conditioned is provided with a primary air conditioner 10, and a plurality of room units which may take the form of so-called induction units 11 or fan-coil units 12, with a unit 11 or 12 being in air communication with each space to be conditioned. The choice of a unit 11 or 12 will depend on varying circumstances, which need not be elaborated on here; suffice it to say that the invention is applicable to either.

Primary air conditioner 10 comprises a casing 13, in which is located a filter 14, a preheater coil 15, a dehumidifier coil 16, and a fan 17 of any conventional type. Fan 17 is generally of a constant speed type and of sufficient capacity to provide for the necessary air velocity at a unit 11 to produce a desired induction effect when the air discharges within the unit. Air inlet louvers 18 are provided in the casing 13 for controlling the flow of air therethrough. A discharge conduit 19 and branch conduits 20 are provided for connecting the fan to the various units 11. It will be appreciated that primary air conditioner 10 is needed only in those buildings utilizing induction units 11.

Each induction unit 11 contains a heat-exchange coil 21, a plenum chamber 22, an air discharge nozzle 23, and also an air outlet 24 from which the air is discharged into the room to be conditioned.

Fan coil units 12 comprise a heat-exchange coil 25, and a fan 26 supported by any particular means such as a baffle 27. Air from the room to be conditioned is drawn in the unit 12 by way of inlet openings 28 and discharged therefrom by way of discharge opening 29.

A chilled water circuit and a heated water circuit are provided for supplying chilled and heated water to units 11 and 12.

The chilled water circuit includes a water pump 30 connected by way of line 31 to a water cooler 32. A discharge line 33 leads from the water cooler to a chilled water supply header 34. A plurality of take-off risers 35 lead from header 34 to the various parts of the building that need conditioning. Lines 36 lead from risers 35 to the cold water inlet of a unit water control valve 37. By-pass line 38 extends from discharge line 33 back to the inlet of the pump 30 for a purpose to be later explained. One-way pressure relief valve 39 is connected into line 38. A supply line 40 and a discharge line 41 are provided in cooler 32 for circulating any desired fluid through the cooler to chill the water flowing therethrough.

The heated water circuit comprises a water pump 42, connected by way of a line 43 to a water heater 44. A discharge line 45 leads from a heater 44 to a hot water header 46. A plurality of heated water risers 47 lead from header 46. Take-off lines 48 lead from risers 47 to the heated water inlet of valves 37. A by-pass line 49 leads from discharge line 45 back to the inlet of pump 42 and contains therein a one-way pressure relief valve 50. A supply line 51 and a discharge line 52 are provided in heater 44 for circulating any desired fluid through the heater to heat the water flowing therethrough.

From valves 37 a discharge line 53 leads to coil 21 or 25, as the case may be. Zoned water return lines 54 are provided and are connected to the outlet of coils 21 and 25 by way of lines 55. Zoned return lines 54 lead to thermostatically controlled diverting valves 56, controlled by bulbs 57 connected thereto by way of capillaries 58 in a manner well known in the art. Valves 56 divert water into a heated water line 59 or a chilled water line 60, dependent on a predetermined set design temperature, for example Lines 59 lead to a heated water return header 61, and lines 60 lead to a chilled water return header 62. A heated take-01f line 63 and a chilled water take-off line 64 lead from return headers 61 and 62 respectively to a pump inlet header 65. From pump inlet header 65, inlet line 66 leads to chilled water pump 30, and an inlet line 67 leads to a heated water pump 42. A thermostat 68 is provided to control each valve 37 of the various units 11 or 12.

OPERATION During the greater part of the year, the outside temperature is such that some rooms will require cooling (sunlit rooms) while others require heating (shaded rooms).

For those rooms requiring cooling, water chilled in cooler 32 flows by way of line 33 to header34. Chilled water exits header ,34 by way of risers 35, and flows from risers 35 by way of lines 36 to valves 37. Thermostats 68 position valves 37 to such a position that no heated water flow is permitted and chilled Water only is allowed to pass through coils 21 and 25. Valves 37 are modulating, dependent on the amount of cooling required in any particular room.

For those rooms requiring heating, water heated in heater 44 flows by way of lines 45 into hot water header 46, whence the water flows into risers 47 and lines 48 to the various valves 37. Thermostats 68 position valves 37 to such a position that no chilled water flow is permitted, and heated water only is allowed to pass through coils 21 and 25. Valves 37 again are modulating, dependent on the amount of heating required in any particular room.

Returned water flowing through zoned water return lines 54 then is diverted by valve 56 into line 59 or line 60 for flow to heated water return header 61, or to chilled water return header 62, depending on its temperature as determined by bulb 57.

From heated water header 61, the water flows by Way of heated water take-01f line 63 to pump inlet header 65 and thence by way of line 67 to heated water pump 42 to complete the heated water circuit. From chilled water header 62, the water flows by way of chilled water takeoff line- 64 to pump inlet header 65 and thence by way of line 66 topump 30 to complete the chilled water circuit.

Should conditions be such that flowof water to either pump 30 or pump 42 is greater than can be accommodated, water header 65 allows this excess water to flow to the alternate pump.

In those rooms served by fan-coil units 12, room air enters the units by way of inlet openings 28 under the influence of fans 26. The room air then flows over coils 25, giving up its heat to the chilled water flow within the coils or picking up heat from the heated water. flow, and then exists the unit by way of outlet openings 29 for returnto the rooms.

With respect to the induction units 11, outside air is drawn into primary air conditioner 10, purified by filter 14 and dehumidified in passing over coil 16. Coil 16 is supplied with a chilled heat-exchange fluid derived from any suitable source. The air is then delivered under the influence of fans 17 to the various induction units by way of conduit 19 and branch conduit 20. The air then flows through nozzle 23, and in so doing induces a flow of room air through coils 21. The room air gives up its heat to the chilled water flowing through coils 21, or picks up heat from the heated water flow, and then mixes with the incoming primary air for return to the room by way of outlets 24.

It will be noted that the zoning arrangement for the returns is such that the returned water from any one particular zone will be either relatively warm or relatively cold, generally depending on the exposure; i.e., ordinarily all the rooms in any one zone will either be heating or cooling, depending on the outside conditions. As was pointed out hereinabove, the rooms are zoned on just such a basis. The arrangement then is such that relatively warm water can be separated from relatively cold return water to improve the overall system efficiency. Since the individual room units are simultaneously supplied with heated and chilled water, the warm returned water flows to the water heater while the cool returned water flows to the water cooler.

From the above it can be seen that the zoning of returned Water is of importance only during those times of the year when some rooms need heating, while other rooms need cooling (intermediate season). However, in the great majority of office buildings this occurs during the major part of the year depending, of course, on the particular location of the building.

During extremely hot weather (summer season), practically speaking, all rooms will require cooling and the returned water all flows to cooler 32. Heater 44 is kept operative to supply heat to those isolated rooms that may require it. Conversely, during extremely cold weather (winter season), practically speaking, all rooms will require heating and the returned Water all flows to heater 44. Cooler 32 is kept operative to supply chilled water to those few isolated rooms that may require it.

The purpose of by-pass lines 38 and 49 is to allow for continuous water flow through the cooler 32 during the winter season, or through heater 44 during the summer season. This is to maintain proper water pressure so that in those isolated instances when either chilled or heated water is called for, there will be instantaneous flow.

While 75 has been designated as the dividing temperature between chilled return fluid and heated returned fluid, it will be apparent that this temperature will vary according to the locality, type of building construction, and many other factors. Sutfice it to say that, dependent on a preselected temperature, returned water flows to the heater or cooler, depending on whether it is above or below the preselected temperature.

As used herein, the term water means any suitable heat-exchange liquid or brine which may be used effectively as a heat-exchange medium.

I wish it to be understood that my invention is not to be limited to the specific constructions and arrangements shown and described, except only insofar as the claims may be so limited, as it will be apparent to those skilled in the art that changes may be made without departing from the principles of the invention.

What is claimed is:

1. A method of air conditioning multi-room buildings comprising the steps of simultaneously making available a chilled and a heated heat-exchange fluid to said rooms; supplying said chilled fluid and circulating room air in heat-exchange relation with said chilled fluid when cooling is required; supplying said heated fluid and circulating room air in heat exchange relation with said heated fluid when heating is required; returning said heat-exchange fluid through a plurality of common returns to a fluid heater or a fluid cooler; and routing said fluid within any of said common returns to said heater or said cooler dependent on the temperature of said fluid.

2. An air conditioning system for multi-room buildings comprising a plurality of heat-exchange coils in air communication with respective rooms; means for flowing room air over said coils in heat-exchange relation therewith; a chilled liquid circuit including a cooler for supplying a chilled heat-exchange fluid to said coils; a heated liquid circuit including a heater for supplying a heated heatexchange to said coils; a plurality of common return lines for flow of heat-exchange fluid from said coils to said heater and cooler; and means for routing said fluid within any said common return line to said heater or said cooler depending on the temperature of said fluid.

3. An air conditioning system as set out in claim 2 and fluid flow connections between each said common return line and those coils in air communication with rooms requiring heating or cooling at the same time.

4. An air conditioning system for multi-room buildings comprising a plurality of heat-exchange coils in air communication with respective rooms; means for flowing room air over said coils in heat-exchange relation therewith; a chilled liquid circuit including a cooler for supplying a chilled heat-exchange fluid to said coils; a heated liquid circuit including a heater for supplying a heated heatexchange fluid to said coils; valve means selectively operable for flowing either said chilled or said heated liquid through said heat-exchange coils; .a plurality of common return lines for flow of heat-exchange fluid from said coils to said heater and cooler; and means for routing said fluid within any said common return line to said heater or said cooler depending on the temperature of said fluid.

5. An .air conditioning system as set out in claim 4 and fluid flow connections between each said common return line and those coils in air communication with rooms requiring heating or cooling at the same time.

References Cited by the Examiner UNITED STATES PATENTS ROBERT A. OLEARY, Primary Examiner.

JAMES W. WESTHAVER, Examiner.

C. SUKALO, Assistant Examiner. 

1. A METHOD OF AIR CONDITIONING MULTI-ROOM BUILDINGS COMPRISING THE STEPS OF SIMULTANEOUSLY MAKING AVAILABLE A CHILLED AND A HEATED HEAT-EXCHANGE FLUID TO SAID ROOMS; SUPPLYING SAID CHILLED FLUID AND CIRCULATING ROOM AIR IN HEAT-EXCHANGE RELATION WITH SAID CHILLED FLUID WHEN COOLING IS REQUIRED; SUPPLYING SAID HEATED FLUID AND CIRCULATING ROOM AIR IN HEAT EXCHANGE RELATION WITH SAID HEATED FLUID WHEN HEATING IS REQUIRED; RETURNING SAID HEAT-EXCHANGE FLUID THROUGH A PLURALITY OF COMMON RETURNS TO A FLUID HEATER OR A FLUID COOLER; AND ROUTING SAID FLUID WITHIN ANY OF SAID COMMON RETURNS TO SAID HEATER OR SAID COOLER DEPENDENT ON THE TEMPERATURE OF SAID FLUID. 